Vitamin B12 and Folate Status in Cognitively Healthy Older Adults and Associations with Cognitive Performance

Objectives To determine prevalence of vitamin B12 and folate deficiency and associations with cognitive performance in participants recruited for the Cognitive Health in Ageing Register: Investigational, Observational, and Trial Studies in Dementia Research: Prospective Readiness cOhort Study (CHARIOTPRO) SubStudy (CPRO-SS). Design Cross-sectional analysis of data collected in the screening phase for the CPRO-SS. Setting Participants were recruited from the Chariot Register at Imperial College London comprising approximately 39,000 community dwelling volunteers. Participants Community dwelling individuals aged 60–85 years with B vitamin biomarker measures available were included (n=1946). After medical history and other exclusions, 1347 cognitively healthy participants were included for analysis of cognitive data. Measurements Cognitive status was assessed with the Repeatable Battery for Neuropsychological Status (RBANS). Assays included vitamin B12 and folate, followed by serum methylmalonic acid and homocysteine levels for those with low vitamin B12. Gender-specific linear regression analysis was performed for associations between cognition and biomarkers. Non-gender specific regression for groups graded by B vitamin deficiency severity were also performed. Results Vitamin B12 deficiency ( Conclusion Older men and women are prone to vitamin B12 deficiency with associated subtle and different domain-specific disruptive effects in measures of memory and attention. Elevated homocysteine and methylmalonic acid contributed to poorer cognitive performance. Novel groups at particular risk of cognitive deficit were identified for future interventional studies in this field.